using System;
using iTextSharp.text;
using iTextSharp.text.pdf;
/*
 * $Id: JBIG2Image.java 3715 2009-02-23 15:02:23Z blowagie $
 *
 * Copyright 2009 by Nigel Kerr.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999-2009 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000-2009 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

namespace iTextSharp.text.pdf.codec {

    /**
    * Support for JBIG2 Images.
    * This class assumes that we are always embedding into a pdf.
    * 
    * @since 2.1.5
    */
    public class JBIG2Image {

        /**
        * Gets a byte array that can be used as a /JBIG2Globals,
        * or null if not applicable to the given jbig2.
        * @param   ra  an random access file or array
        * @return  a byte array
        */
        public static byte[] GetGlobalSegment(RandomAccessFileOrArray ra ) {
            try {
                JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
                sr.Read();
                return sr.GetGlobal(true);
            } catch {
                return null;
            }
        }
        
        /**
        * returns an Image representing the given page.
        * @param ra    the file or array containing the image
        * @param page  the page number of the image
        * @return  an Image object
        */
        public static Image GetJbig2Image(RandomAccessFileOrArray ra, int page) {
            if (page < 1)
                throw new ArgumentException("The page number must be >= 1.");
            
            JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
            sr.Read();
            JBIG2SegmentReader.JBIG2Page p = sr.GetPage(page);
            Image img = new ImgJBIG2(p.pageBitmapWidth, p.pageBitmapHeight, p.GetData(true), sr.GetGlobal(true));
            return img;
        }

        /***
        * Gets the number of pages in a JBIG2 image.
        * @param ra    a random acces file array containing a JBIG2 image
        * @return  the number of pages
        */
        public static int GetNumberOfPages(RandomAccessFileOrArray ra) {
            JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
            sr.Read();
            return sr.NumberOfPages();
        }
    }
}